Respuesta :

Answer:

Step-by-step explanation:

This is a ratio problem using triangles. 8 and x are part of the smallest triangle at the top. The next triangle down has a side length of 8 + 9 which is 17, and the other side length of x + 12. So we proportion the problem like that:

[tex]\frac{8}{x} =\frac{17}{12+x}[/tex]

Then cross multiply to get

8(12 + x) = 17x and

96 + 8x = 17x and

96 = 9x so

x = 10.666666

or 10.7

The last choice in the list.